A dual-band four-beam 1-bit hybrid active/passive metasurface reflectarray antenna

Abstract This paper presents a dual-band reflectarray antenna based on a 1-bit hybrid active/passive metasurface, achieving independent four-beam radiation at frequencies of 5.8 and 9.7 GHz. The proposed unit cell integrates an active double-split square ring with PIN diodes for 180° phase switching at 5.8 GHz, and a passive cross-shaped patch for 180° phase control at 9.7 GHz. A chessboard-like coding arrangement enables independent beam steering at both frequencies. Experimental results from a fabricated 15 × 15 metasurface prototype show stable four-beam operation, with measured steering angles of 19° and 12.1°, and 3-dB beamwidths of 10.2° and 11.5° at 5.8 and 9.7 GHz, respectively, validating good agreement with simulations. The proposed metasurface demonstrates significant promise for applications in multiband radar and communication systems requiring compact, low-profile, reconfigurable antennas.